Helicopters take off from and land at airports, as well as a multitude of off-airport sites. However, helicopters are often flown differently around airports than at other landing zones. This may be due to several reasons, including noise abatement or fixed-wing air traffic.
When a helicopter flies an instrument landing approach to an airport, the helicopter is typically flown like a fixed-wing aircraft; that is to say, a high speed is maintained until decision height (DH). Without knowing that the helicopter is flying an instrument approach at an airport, like a fixed-wing aircraft, a flight profile may be the same or similar to that of a typical controlled flight into terrain (CFIT) accident.
On the other hand, if the helicopter's pilot is not intending to land at the airport, then an Enhanced Ground Proximity Warning System (EGPWS) should warn the helicopter's pilot of the helicopter of a terrain alert situation. However, it is not known in prior art for a helicopter EGPWS to automatically make the decision of whether or not to use airport information (such as, airport location (latitude, longitude), elevation, and runway heading) to modulate EGPWS algorithms for avoiding nuisance alerts.
Therefore, there is an unmet need in the art for a helicopter EGPWS to automatically know when (and when not) to use airport information to modulate EGPWS algorithms. There is also an unmet need in the art for monitoring a takeoff of the helicopter from an airport differently than monitoring an approach by a helicopter to an airport.